most of them have been used. they're extremely hot, highly radioactive, and experts say they need to be kept cool for 30 to 40 years. the rods are stored in the pool about 20 meters above ground. the water traps radiation and keeps the rods cool. but a hydrogen explosion in 2011 weakened the building's structure. experts say the rods must be moved to a safer place. managers of tokyo electric power company have been preparing to start the job for the last two and a half years. they plan to lift the rods out with a crane. but the bidding was too weak to support it. so workers built a steel frame. they will transfer the rods to containers that can seal in radiation. they had then move these to a storing facility within the compound and put them back into water. the job is far from straightforward. the workers have to maneuver the rods under water to prevent any radiation from escaping. and they will have to cope with high levels of radiation. up to 200 micro sieverts per hour. >> translator: the working environment